1. Field of Invention
The present invention relates to an ink supply device, and more particularly to an ink cartridge for supplying ink to the print head of ink-jet printer.
2. Description of Related Art
In general, ink cartridge inside an ink-jet printer has a cartridge body filled with ink. The ink is printed on the surface of paper through the ink outlet of ink cartridge. Known ink cartridge can be substantially classified into two types: ink cartridges with absorption material and ink cartridges without absorption material. Most of the conventional ink cartridges possess absorption material, such as a sponge or the like, but such the absorption material not only occupies the space of ink storage chamber of ink cartridge, but also left therein large amount of ink. Once discarded, the environment will be polluted. In addition, due to that it is difficult to recycle, works on environmental protection become complicated. Ink cartridge without absorption material can avoid the said defects. For example, Chinese Patent No. 0326813.9 discloses an printer's ink cartridge with valve in which a negative pressure on the ink outlet of the ink cartridge is kept by means of a pressure regulator mechanism which is comprised of a front valve body, a rear valve body, a valve film, a spring etc. Even though such a mechanism may continuously and uniformly supply the ink and assure printing quality, it is complex in structure and high in manufacturing cost. Also, it is difficult to assure the quality of the pressure regulator mechanism.